DNS handed out by DHCP
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We have a Netgate 5100. Part of what we use it for is a DHCP server. When we first set it up to do this last year, we had no issues. But starting this year, it sporadically doesn't hand out the proper DNS servers. We have it set to hand out our AD server and its own address. It will always hand out the AD server address, but sporadically will not hand out it's own address. This happens to computers whether they are wired or wireless, but, as I said, doesn't happen to all of them. Access to the internet is via the Netgate's IP address, so when this happens people can't reach the internet. To fix it, we have to manually assign the DNS servers. Has anybody run into this or know why it might be happening?
Thanks.
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@jlinesabi seems like a bad setup to be honest. Point your clients to your AD dns if your an AD shop, then have your ad point to pfsense to resolve internet addresses.
Handing out multiple NSers to client - you have no idea which one they might ask.. So your saying the ad dns can not resolve public like google.com and your dns on pfsense can not resolve your AD stuff.. So your clients are going to have a hard time no matter what.
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I 100% agree with @johnpoz here. With a Microsoft Active Directory shop, you want everything DHCP and DNS related to be handled by Microsoft products in my opinion. Most definitely DNS! And because of the seamless dynamic DNS updating performed by Microsoft's DHCP server, it is better and easier to run DHCP there instead of on pfSense.
And handing out two different DNS servers each of which may have some zones unknown to the other server is sure to cause an issue as described by John. Clients do NOT use multiple DNS servers sequentially until one of them finds an answer. They ask one of the servers randomly, and if that server says NXDOMAIN (non-existent domain), then the client does not ask the next server because it has already gotten an answer. The only time clients try one server and then move on to the next in a multiple DNS server configuration is when the first server is completely dead and does not answer at all.
